Managing for Healthy Forests
Across the urban to rural landscape gradient, forests are a natural climate solution. By way of carbon sequestration and storage, trees and forests mitigate climate change. They also function to ameliorate the effects of climate change. Sound forest management is critical to promote the health and function of Connecticut forests, so that they remain carbon sinks and an effective component of natural climate solutions. A portfolio of management options exist for foresters, landowners, stewards, and policy makers. Collectively, we can manage for healthy forests through a well-balanced, and often combined implementation of the following management options at varied temporal and spatial scales.
Keeping forests as forests can be achieved through:
- Legacy planning;
- Protecting ecologically important systems around the world;
- Wildlife preserves;
- Reserve management, if protective measures are put in place.
Also known as reserve management, passive management, and non-extractive management. To be most effective, this approach requires a collaborative active decision-making process based on stand-level or landscape-level data. This approach is best suited for rich, protected sites that have low risk for disturbance. It is not well suited for forests in need of restoration or fire, or those with forest health issues or significant climate vulnerabilities. Reserve management also poses a significant risk of leakage and declines in carbon sequestration rates.
Reforestation is the process of planting trees or prescribing regeneration harvests where regeneration lacks in a forest. Afforestation is the establishment of trees in an area that previously had no tree cover, which over time creates a new forest. Examples of this approach are:
- Establishing functional riparian buffers;
- Urban tree planting;
- Forest restoration.
Volunteers planting a tree in a Connecticut city.
Sound forest management diversifies conditions across the landscape and promotes forest health, resilience, and adaptability. It employs the use of skilled professionals to collect data and use scientifically-derived information to make management decisions to achieve specific goals. Active forest management can easily be integrated with other management options, and is often employed to achieve multiple ecological, social/cultural, and economic goals. It is particularly beneficial where forest biodiversity and health currently lack and where forests are particularly vulnerable to the impacts of climate change.
Active forest management approaches that promote forest health, resilience, and carbon are:
Extended rotations, or increasing the time between harvests to grow larger trees. This provides a substitution benefit and can be paired with other actions to increase and improve stand structure. It is not suitable for all forest stands, but can strike a balance between maintaining bigger trees to store more carbon and smaller trees to sequester more carbon.
Thinnings to improve the growth of remaining trees. This reduces competition for light and other resources through silvicultural prescriptions, like single tree selection, group selection, crop tree release, timber stand improvement, and variable density thinnings.
Thinning conducted to promote the health and vigor of residual oaks.
Structural complexity enhancement. Usually by emulating natural disturbance regimes, increasing structural complexity diversifies the arrangement and spacing of trees, increases size and age class diversity, and retains large trees, tip-ups, cavities, and other important ecological features. Enhancing structural complexity may be the most effective way of promoting forest resilience, biodiversity, and carbon.
White pine damage from Hurricane Sandy, 2012 Hamden, CT.
White pine seed tree harvest emulated disturbance in Mansfield, CT.
Increasing the proportion of younger age classes. This promotes species-specific regeneration through silvicultural prescriptions like group selections, patch cuts, and regular and irregular shelterwood systems. Though this will result in a temporary loss of carbon until the young trees occupy the new space, it will increase stand-level sequestration over time. It can also advance forest resilience through higher age class and greater species diversity. It benefits wildlife, but also creates a need to protect regeneration from herbivory (i.e., deer browse).
The establishment of a younger age class following an irregular shelterwood harvest.
Retaining big trees. Large trees disproportionately contribute to forest carbon stocks. Retaining legacy trees, conducting crop tree releases, implementing longer cutting cycles all increase the density of big trees. Large trees, which may (but not necessarily) be old, are a source of strong locally-adapted genetics. Though their retention promotes healthy stand genetics, and adds to structural complexity and biodiversity, big tree retention may reduce the economic value of the harvest.
A big tree retained as a biological legacy.
Retaining and increasing deadwood. Keeping and creating standing dead trees and current and future downed coarse wood materials can be done through girdling standing trees and felling and leaving trees. It is important to have a range of dead wood sizes, with the understanding that larger deadwood has great ecological value. Though there may be an initial decline in carbon sequestration, doing this protects soil health, increases carbon stocks, can increase carbon sequestration, and promotes resilience.
Increasing stocking. This is particularly relevant to reforestation and afforestation efforts, where stocking is low or forest cover is lacking.
A prescribed burn was used as this pitch pine regeneration method. Now, there are more trees growing at this site than before.
Increasing species diversity. Like with structural complexity, species diversity promotes forest health, resilience, and adaptability. It can increase carbon stocks and another forest functions because more niches are filled and the functional diversity of the stand is enhanced. As such, when managed for species diversity, forests have a greater representation of tolerances, recovery strategies, defense strategies, reproductive strategies, and more.
Planning harvests to retain quality trees and limit residual damage. Retaining quality trees during a harvest and reducing their damage invests in the future of the forest. It not only helps to ensure healthy forest conditions for future carbon sequestration and storage and reduces emissions from decay and mortality, but it increases the potential for long-term durable wood products.
Increasing the proportion of durable wood products. Harvesting local and regional wood that produces long-lived products promotes the health of our planet and viability of our local and regional economies. It reduces our use of other high greenhouse gas emission materials, like concrete, steel, and plastic, while preventing leakage. It also can increase net forest carbon storage if the durable wood product is used for longer than the equal amount of wood growth. Though not possible in all stands, an actively managed stand can in fact have greater carbon storage than a passively managed stand.
Lumber harvested from CT State Forests, milled at DEEP's Portland Complex and used for State Park picnic benches.